/******************************************************************************
* Copyright (c) 2015-2022 jiangxiaogang<kerndev@foxmail.com>
*
* This file is part of KLite distribution.
*
* KLite is free software, you can redistribute it and/or modify it under
* the MIT Licence.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
******************************************************************************/
#include "kernel.h"

#define NVIC_INT_CTRL (*((volatile uint32_t *)0xE000ED04))
#define PEND_INT_SET  (1<<28)

void cpu_contex_switch(void)
{
	NVIC_INT_CTRL = PEND_INT_SET;
}

void *cpu_contex_init(void *stack_base, void *stack_top, void *entry, void *arg, void *exit)
{
	uint32_t *sp;
	sp = (uint32_t *)(((uint32_t)stack_top) & 0xFFFFFFF8);
	*(--sp) = 0x01000000;               // xPSR
	*(--sp) = (uint32_t)entry;          // PC
	*(--sp) = (uint32_t)exit;           // R14(LR)
	*(--sp) = 0;                        // R12
	*(--sp) = 0;                        // R3
	*(--sp) = 0;                        // R2
	*(--sp) = 0;                        // R1
	*(--sp) = (uint32_t)arg;            // R0

	*(--sp) = 0xFFFFFFF9;               // LR(EXC_RETURN)
	*(--sp) = 0;                        // R11
	*(--sp) = 0;                        // R10
	*(--sp) = 0;                        // R9
	*(--sp) = 0;                        // R8
	*(--sp) = 0;                        // R7
	*(--sp) = 0;                        // R6
	*(--sp) = 0;                        // R5
	*(--sp) = 0;                        // R4
	return sp;
}
